Reproductive performance of Arab mares in the Kingdom of Saudi Arabia.

The research evaluates the reproductive performance of Arab mares in Saudi Arabia by surveying the managers of 26 stud farms that house a total of 1014 Arab mares across five districts.

Study Methodology

• The study was based on a survey, in which managers of 26 stud farms containing 1014 Arab mares spread across five districts were asked to answer questions touching on the reproductive efficiency of the mares.

Reproductive Performance Parameters

• The mean age for initial mating of the mares was observed to be approximately 3.06 ± 0.5 years.
• Mating tended to happen both in winter and throughout the year.
• The majority (76.9%) of matings were natural.
• The average estrus cycle, period between each heat, was around 19.57 ± 1.8 days, with each heat/estrus duration being about 6.58 ± 1 days.
• The average first service (success of the mare getting pregnant after first mating attempt) and overall pregnancy rates were reported as 52.71 ± 20.2% and 83.72 ± 15.0% respectively.
• On average, 1.46 ± 0.3 mating cycles were needed for a successful pregnancy.
• The average gestation (pregnancy) period for mares was approximately 335.5 ± 10.2 days.
• The study found a statistically significant shorter gestation period for mares that were mated by day 9 postpartum than those mated later.
• No influence of postpartum interval, district, or season on fertility was observed.
• The ratio of stallion to mares varied considerably, ranging from 1:4 to 1:24, but this had no correlation with the pregnancy rates or the number of mating cycles needed for a pregnancy.

Key Conclusions

• The breeding cycle of Arab mares in Saudi Arabia is not strictly seasonal and they can reproduce efficiently throughout the year.
• No difference in fertility was found across different districts and seasons.
• Photoperiodic changes (naturally occurring variations in light and dark periods) and the associated shifts in the hypothalamic-hypophyseal axis (regulatory region of the brain that influences hormone release) common in temperate regions are usually tied to seasonal mare breeding behaviour. But this seasonal reproductive pattern is not seen in this subtropical region.
• The study suggests that the shorter gestation period in mares mated early after foaling may be due to the nutritional status of the mares.
• This study provides the first data on the reproductive performance of Arab mares in Saudi Arabia, which could assist with future management concerning these horses.